1. Field of the Invention
This invention has as its object a process for producing pressure sensors and other similar devices in which a close bond must be obtained between a sealing glass and another material under the effect of heat. The process applies particularly to the case where an electric field of some tens of volts to some thousands of volts is applied between the glass and the other material placed a slight distance from one another to accomplish so-called electrostatic welding.
2. Description of the Prior Art
The best known case is that of glass or silicon welding, a case in which a more or less thick layer of silicon dioxide is always present on the surface of the silicon. Depending on its thickness, this layer more or less modifies the welding conditions, particularly temperature conditions.
The technology makes it possible to perform the welding in a wide temperature range without deformation of the parts being welded even at the softening temperature of the glass. The process is particularly suitable for the use of a very thin glass.
The process consists in floating the unit to be welded on a moltel metal bath, particularly of tin, under a vacuum or a low pressure of a reducing gas during the welding operation. The metal preferable is tin. Use of a tin bath for the continuous production of flat glass is well known since the development of the process by the British company PILKINTON.